Patent Application
20130268036
This disclosure generally relates to treatment of blood vessel disorders. More specifically, this disclosure relates to using vapor therapy to reduce an inner diameter of a vessel in the leg of a patient.
The human venous system of the lower limb consists essentially of the superficial venous system and the deep venous system with perforating veins connecting the two systems. The superficial system includes the great saphenous, small saphenous and the lateral saphenous systems. The deep venous system includes the anterior and posterior tibial veins which unite to form the popliteal vein, which in turn becomes the femoral vein when joined by the short saphenous vein.
The venous systems contain numerous one-way valves for facilitating blood flow back to the heart. Venous valves are usually bicuspid valves, with each cusp forming a sack or reservoir for blood when, under pressure, forces the free surfaces of the cusps together to prevent retrograde flow of the blood and allows antegrade flow to the heart. When an incompetent valve is in the flow path of retrograde flow toward the foot, the valve is unable to close because the cusps do not form a proper seal and retrograde flow of blood cannot be stopped.
Incompetence in the venous system can result from vein dilation, which causes the veins to swell with additional blood. Separation of the cusps of the venous valve at the commissure may occur as a result. The leaflets are stretched by the dilation of the vein and concomitant increase in the vein diameter which the leaflets traverse. Stretching of the leaflets of the venous valve results in redundancy which allows the leaflets to fold on themselves and leave the valve open. This is called prolapse, which can allow reflux of blood in the vein. Eventually the venous valve fails, thereby increasing the strain and pressure on the lower venous sections and overlying tissues. Two venous diseases which often involve vein dilation are varicose veins and chronic venous insufficiency.
The varicose vein condition includes dilatation and tortuosity of the superficial veins of the lower limb, resulting in unsightly protrusions or discoloration, ‘heaviness’ in the lower limbs, itching, pain, and ulceration. Varicose veins often involve incompetence of one or more venous valves, which allow reflux of blood from the deep venous system to the superficial venous system or reflux within the superficial system.
Current varicose vein treatments include invasive open surgical procedures such as vein stripping and occasionally vein grafting, venous valvuloplasty and the implantation of various prosthetic devices. The removal of varicose veins from the body can be a tedious, time-consuming procedure and can be a painful and slow healing process. Complications including scarring and the loss of the vein for future potential cardiac and other by-pass procedures may also result. Along with the complications and risks of invasive open surgery, varicose veins may persist or recur, particularly when the valvular problem is not corrected. Due to the long, arduous, and tedious nature of the surgical procedure, treating multiple venous sections can exceed the physical stamina of the physician, and thus render complete treatment of the varicose vein conditions impractical.
Newer, less invasive therapies to treat varicose veins include intralumenal treatments to shrink and/or create an injury to the vein wall thereby facilitating the collapse of the inner lumen. These therapies include sclerotherapy, as well as catheter, energy-based treatments such as laser, Radio Frequency (RF), or resistive heat (heater coil) that effectively elevate the temperature of the vein wall to cause collagen contraction, an inflammatory response and endothelial damage. Sclerotherapy, or delivery of a sclerosant directly to the vein wall, is typically not used with the larger trunk veins due to treatment complications of large migrating sclerosant boluses. Laser energy delivery can result in extremely high tissue temperatures which can lead to pain, bruising and thrombophlebitis. RF therapy is typically associated with lengthy treatment times, and resistive heater coil treatments can be ineffective due to inconsistent vein wall contact (especially in larger vessels). The catheter based treatments such as laser, resistive heater coil and RF energy delivery also typically require external vein compression to improve energy coupling to the vein wall. This is time consuming and can again lead to inconsistent results. In addition, due to the size and/or stiffness of the catheter shaft and laser fibers, none of these therapies are currently being used to treat tortuous surface varicosities or larger spider veins. They are currently limited in their use to large trunk veins such as the great saphenous vein (GSV). Tortuous surface varicosities are currently treated with sclerotherapy and ambulatory phlembectomy, while larger spider veins are currently only treated with sclerotherapy.
One aspect of the invention provides a method of delivering therapy to a vein. The method includes the following steps: inserting a structural sheath into the vein, the structural sheath being configured to prevent collapse of the vein due to spasm or via the administration of tumescent anesthesia; advancing a vapor delivery shaft into the catheter sheath; positioning a vapor delivery tip of the vapor delivery shaft distally of the catheter sheath; and delivering vapor to the vein through the vapor delivery tip to, e.g., shrink the vein with the vapor.
In some embodiments, the vapor may be generated remotely from the vapor delivery shaft, and in other embodiments, the vapor may be generated within the vapor delivery shaft.
In some embodiments, prior to the delivering step, the structural sheath is retracted proximally along the vapor delivery shaft to expose a portion of the vapor delivery shaft. The exposed portion of the vapor delivery shaft may form a hot zone having a length of approximately 5 cm to 15 cm. In some embodiments, the retracting step includes the step of retracting the structural sheath until a portion of the sheath engages a fitting extending from the vapor delivery shaft.
Some embodiments of the invention include the step of pulling the structural sheath and the vapor delivery shaft proximally along the vein during the delivering vapor step. Such embodiments may also include the step of maintaining a relative position between the catheter sheath and the vapor delivery shaft during the pulling step.
Another aspect of the invention provides a method of treating a vessel. The method includes the following steps: inserting a structural sheath into a vessel to be treated; applying tumescent anesthesia around the vessel; preventing the vessel from collapsing due to the tumescent anesthesia with the structural sheath; advancing a vapor delivery catheter into the sheath to position delivery vapor ports of the catheter within the vessel; and delivering vapor through the vapor delivery ports to treat the vessel by, e.g., shrinking the vessel.
Some embodiments of this aspect of the invention include the step of pulling the structural sheath and the vapor delivery catheter proximally within the vein during the delivering step. The method may also include the steps of stopping the pulling of the structural sheath and the vapor delivery catheter when the catheter reaches a feeder vein to be treated; steering the delivery vapor ports into or towards the feeder vein; and delivering vapor through the vapor delivery ports into the feeder vein to treat the feeder vein.
Yet another aspect of the invention provides a vapor delivery catheter system having a structural sheath adapted to be inserted into a vein; and a vapor delivery shaft adapted to be surrounded by the structural sheath, the vapor delivery shaft including a vapor delivery port at a distal end of the shaft and a fitting at a proximal end of the shaft, the fitting being adapted to engage with the structural sheath when the vapor delivery port extends from a distal end of the sheath. In some embodiments, the fitting is further adapted to attach the sheath to the vapor delivery shaft so that the sheath and the shaft can be moved as a unit.
In some embodiments, the sheath has markings at the distal end of the sheath adapted to alert the user when the sheath is about to exit the entry site. The markings may be regularly spaced markings adapted to indicate depth of insertion of the sheath and at least one distal marking distinct from the regularly spaced markings at the distal end of the sheath.
The novel features of the invention are set forth with particularity in the claims that follow. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which:
The disclosure relates generally to systems and their methods of use to treat venous insufficiency. More particularly, the invention relates to vapor treatment of a vein to reduce its inner diameter to minimize and/or eliminate blood flow through the vein. The therapy is generally used to divert the flow of blood from an insufficient vein to a vein that is sufficient.
The vapor treatments described herein can be used to treat any vein, such as trunk vessels (e.g., a great or small saphenous vein), sub-truncal veins (e.g., accessory vessels) or spider veins. The veins treated need not be varicose, however this is typically the case. The invention is not, however, limited to the treatment of the veins and the anatomical locations of the veins that are described herein. For example, the invention can be used to treat veins outside the leg region, such as abdominal varicosities, hemorrhoids, varicoceles, etc.
The treatments described herein generally include generating and delivering relatively high temperature (e.g., without limitation, greater than 37° C.) vapor through a delivery device to the lumen of a vein to reduce the inner diameter of the vein. A significant benefit of vapor delivery to reduce the lumen of the vessel is that it flows to the internal surfaces of the vein due to the increased pressure of the vapor and does not require external compression of the vein to enhance energy transfer of the device to the vein wall. Another significant benefit of the vapor delivery is the large amount of energy released in the transition of the vapor into the fluid phase. A further significant benefit of the vapor is that it is self-limiting in that it ceases to conduct heat to the vessel wall once temperature equilibrium has been reached between the vapor and the vessel wall. This is unlike other treatments which will continue to deliver energy to the tissue to the point of extensive thermal injury.
The vapor (such as steam) can be generated in a variety of locations in the system. For example, the vapor can be generated in a remote boiler or control console separate from the delivery device, within a handle or handpiece, or within the portion of the elongate member (such as a catheter) that is inserted into the vein. The vapor can be generated in any portion of the elongate member that is either inside or outside of the patient, for example.
This disclosure overcomes a major problem with the previously described catheter-based vapor system and others used in the clinic. Unlike other catheter based treatments such as laser, resistive heater coil and RF energy delivery, the catheter-based vapor system does not require external vein compression to improve energy coupling to the vein wall. The present disclosure improves the therapy by preventing the inadvertent compression and/or undesired spasm of the vein walls which hinders proper vapor dispensation. Embodiments described herein, including apparatus and methods of treating a vein with heat energy while preventing spasm, collapse or reduction in vein diameter prior to vapor therapy, provides this significant improvement.
As described above, any compression of the vessel or movement of the vein wall into the lumen prior and during treatment is not desired. This compression or movement can be due to: administration of tumescent anesthesia and the fluid volume delivery and associated needle stick; administration of anesthetic or cooling fluid (typically 0.9% normal saline) around or on top of the vein; ultrasound probe pressure; or vein spasm (due to irritation of the vein due to catheter placement; cold procedure room; needle stick for local anesthetic; or cold saline drip from catheter tip).
According to some embodiments, such vessel wall movement, luminal diameter reduction or distortion (e.g. flattening), or full lumen collapse (e.g., via administration of tumescent anesthesia) will not allow the vapor to freely flow from the vapor catheter tip exit ports out to the full internal luminal surface of the vein. In some instances, full lumen collapse over the catheter's vapor exit ports can completely block and prevent the delivery of vapor to a collapsed vessel. Therefore, preventing vessel collapse and administering the vapor to the full internal luminal surface of the vein to administer symmetrical and consistent heat energy is important to achieve proper vein shrinkage.
Catheter 100 can further include valve 108 and flush port 110. Valve 108 can be configured to couple the catheter to a control system and/or a vapor source. In some embodiments, the catheter receives vapor from an external source (e.g., a remote boiler), and in other embodiments the catheter generates vapor within the catheter itself. Flush port 110 can facilitate flushing the catheter with, for example, saline or another fluid/gas prior to or after therapy.
In the embodiment illustrated in
As in the embodiment of
According to the embodiment of
Methods of using the vapor delivery catheters described above will now be discussed. The specific clinical steps to be used are included for illustration purposes and are not specific constraints of this disclosure. First, a micro introducer kit can be used to gain venous access (not shown). The micro introducer kit can comprise, for example, a needle, 0.018 guide wire, and an introducer or, if desired, otherwise access using 18 g needle. Next, the guide wire can be advanced to the Sapheno Femoral Junction (SFJ).
Referring to
Next, catheter shaft 102 can be inserted into the sheath 104 and advanced distally until vapor ports 114 are positioned distal to the end of the sheath, as shown in
As discussed above,
Next, referring to
Next, tumescent anesthesia can be applied in or around the vessel to be treated, as known. The structural sheath is configured to prevent collapse of the vessel due to the tumescent anesthesia, or due to spasm of the vein. In some embodiments, tumescent anesthesia is not applied before therapy.
Referring now to
The vapor delivered by the vapor delivery catheter of this invention may be generated remote from the catheter and delivered to the catheter shaft or it may be generated within the catheter itself, such as in the catheter handle or catheter shaft. Details of one suitable manner of generating vapor within the catheter may be found in US Patent Publ. No. 2011/0264176, the disclosure of which is incorporated herein by reference.
As for additional details pertinent to the present invention, materials and manufacturing techniques may be employed as within the level of those with skill in the relevant art. The same may hold true with respect to method-based aspects of the invention in terms of additional acts commonly or logically employed. Also, it is contemplated that any optional feature of the inventive variations described may be set forth and claimed independently, or in combination with any one or more of the features described herein. Likewise, reference to a singular item, includes the possibility that there are plural of the same items present. More specifically, as used herein and in the appended claims, the singular forms “a,” “and,” “said,” and “the” include plural referents unless the context clearly dictates otherwise. It is further noted that the claims may be drafted to exclude any optional element. As such, this statement is intended to serve as antecedent basis for use of such exclusive terminology as “solely,” “only” and the like in connection with the recitation of claim elements, or use of a “negative” limitation. Unless defined otherwise herein, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The breadth of the present invention is not to be limited by the subject specification, but rather only by the plain meaning of the claim terms employed.
This application claims the benefit of U.S. Application No. 61/620,334, filed Apr. 4, 2012, the disclosure of which is incorporated by reference. All publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61620334 | Apr 2012 | US |
